Hair waving composition



HAIR WAVING COIVIPOSITION Alfred E. Brown, Takoma Park, Md., assignor to The Gillette Company, a corporation of Delaware No Drawing. Application April 23, 1951,

. Serial No. 222,527

12 Claims. (Cl. 16787.1)

My invention relates to a liquid hair waving composition of improved characteristicsand more particularly relates .to an improved waving lotion for waving human hair on the head without the use of heat.

Waving lotions of the type herein comprise as their active component a compound, usually referred to as a reducing agent, which acts to convert the disulfide or cystine bonds of the hair keratin to sulfhydryl groups. This conversion, which is ordinarily effected with the hair wound on curlers or otherwise fixed in a curled condition, is marked by plasticization, of the hair with consequent detensioning thereof, so that upon subsequent rebuilding of the disulfide linkages with the hair still in a wound condition, the hair takes a positive curled set. Therebuilding of the linkages is brought about either by natural oxidative processes alone or, more usually, through the use of so-called neutralizer solutions, which in general are solutions of oxidizing agents such as hydrogen peroxide, potassium bromate, alkaline perborate and the like.

The composition herein utilizes a thiol, i. e., an organic compound containing a sulfhydryl or mercaptan group, as the hair-reducing agent. The thiol is employed in aqueous alkaline solution, the pH of the solution being variable within limits hereinafter indicated. Preferred thiols are those comprising strong polar groups, particularly neutralized acid groups, e. g., ammonium thioglycolate, sodium thioglycolate, the sodium and ammoni um salts of mercaptoethanesulfonic acid and 3- mercapto- 2-hydroxypropanesulfonicYacid, etc.

By the foregoing I do not mean to imply that my invention is based on the discovery that thiols are applicable as hair-reducing ,agents, for this is well known. Rather, my invention is founded on the discovery that the effectiveness of thiols in hair waving maybe greatly improved through the use therewith of, certain auxiliary agents subsequently to be identified. I

As a general rule, the higher the concentration of the thiol compound in a thiol hair waving solution having a given alkaline pH, the shorter the time required to plasticize the hair to the extent necessary to enable the impartation of a permanent wave thereto. And it is also generally true that with a given concentration of thiolcompound,

the thiol to decompose with the formation of malodorous and potentially toxic decomposition products.

In consideration of the foregoing, thiol waving lotions as presently. marketed necessarily represent a compromise, although there isconsiderable deviation among brands, some manufacturers preferring a relatively high concentration of the thiol with a relatively lowpH, others preferring to incjreasethe pH and reduce the thiol content. In any case, to reduce the waving time below the one to two hour periodv ordinarily required, it is necessary to make the pH of the thioglycolate concentration of the lotion so high that maximum wave quality is not obtained.

The present invention aims to generally increase the effectiveness of thiol waving lotions. The invention may be applied in any one of a numberof ways. Thus, through its. use the plasticization of the hair may be markedly speeded up and substantially tighter wave undulations produced without increasing either the concentration of the thiol or the alkalinity of the lotion. Alternatively, .for example, eitheror both the thiol concentration and the alkalinity may be substantially reduced, yet adequate plasticization of the hair achieved in the same or a short er period.

My invention stems from a discovery previously made that the reduction of hair withthiol compounds is accompanied by substantial swelling of the hair. In considering this discovery, it occurred to me that the swelling proved-to be altoether effective in waving hair.

was perhaps as, important'from the standpoint of the permanent waving of hair as the chemical reduction itself. Following through with this thought, I added to a. sample lotion, too weak in thiol for effective waving a small amount of urea, which compound I knew to be capable of swelling hair, yet incapable of disrupting disullide bonds. Testing of this modified lotion seemed to fully confirmthe validity of my hypothesis in that the lotion Moreover'the hair in the waved tresses wa s-found to have suffered very little,"if at all, as a consequence of the wavingtreatment, whereas hair waved to a like degree with the particular thiol, used alone in higher concentration, very' often shows changes in its mechanical properties.

' This surprising result I had 'nowise anticipated. Carrythe higher the pH the. shorter the time required ing my researches further I found, as expected, that the remarkable results could be duplicated with other thiols, but as will be later apparent, I further found that my original hypothesis does not hold in all cases.

My invention is particularly striking in its effects as demonstrated in relation to the thiol cysteine. This compound, used in concentrations and at pH values which are both safe and commercially feasible, does not provide an acceptable wave; indeed, at room temperature it shows so little waving activity that for all practical purposes it-isvalueless for home waving. Upon the addition of a few mols of urea, however, the composition becomes substantially as effective as the conventional ammonium thioglycolate compositions.

While I prefer to use urea itself in the practice of my invention, low molecular weight monoalkyl derivatives of urea, as methyl and ethyl urea, for example, are also applicable. The poly-alkyl derivative, dimethyl urea, for instance, are inoperative, as are urea derivatives comprising aryl groups.

The amount of urea compound included in the waving lotion varies with the identity and concentration of the thiol and further depends on the effects sought. In general, however, compositions within the scope of my invention are from 0.35 to- 0.8 molar in the respect of the 3 thiol and from 0.5 to 4.0 molar in the respect of the urea compound. The pH of the compositions may lie anywhere within the range 8.6 to 9.5. Naturally, I do not mean by the recitation of these limits to encompass compositions which are unsafe or ineffective for hair waving. Thus, when the pH of the composition lies within the upper portion of the stated range, the concentration of the solutes, particularly the thiol, will be generally lower than when the pH lies within the lower portion of such range.

The use of urea to reduce the amount of thiol needed for a given waving effect is of substantial advantage from a commercial standpoint since urea is much less EXPEIF sive than any of the thiols.

In addition to the thiol and urea compound I may include a perfume in the composition; also a wetting agent and a creaming agent. These materials, of course, are old in waving lotions; in fact, it is because of the practice of including a creaming agent that the preparations are referred to as lotions.

In the presence of urea, certain highly active thiols, as ammonium thioglycolate, for instance, tend, in some cases, to over-process the hair. I have discovered that this undesirable effect can be substantially completely eliminated by adding to the lotion a suitable amount of a non-toxic, water soluble, inorganic ammonium salt, such as ammonium sulfate, ammonium chloride or ammonium phosphate, agents of themselves incapable of reducing the disulfide linkages in hair. It is a curious fact that while the ammonium salt'acts by reducing the capacity of the thiol and urea to swell hair, the waving results are affected but very little, if any, by its presence. This property of the ammonium salts, i. e., the property of decreasing hair swelling without adverse efiect on the quality of the wave, is apparently unique and very surprising. Thus, on addition of alkali metal salts, such as sodium sulfate, to operative thiol waving lotions, waving efficiency falls with increasing amounts of deswelling produced. Moreover, when equivalent deswelling is produced by addition of either an ammonium or a sodium salt, it is found that the waving efiiciency of the former lotion is much superior to that of the latter.

The amount of ammonium salt included in the lotion hinges on the identity of the salt and on the extent of deswelling required in order to avoid the over-processing. With excessively high concentrations of the salt, i. e., concentrations such that the molarity of the solution in point of the salt exceeds 3 M, the advantage is largely lost. Normally, the ammonium salt is used in a concentration within the range 0.25 to 2.0 M.

Although one of the major advantages of my -inven tion resides in the fact that it allowsfor the use of cysteine in commercial lotions, Ipreferably practice my invention using ammonium thioglycolate as the thiol component of the lotion.

Most of the significant ammonium thioglycolate-containing compositions are embraced by the limits below:

Thiol concentration Q. DA-0.6M Urea compound concentration 0.5-3.0 M Ammonium salt concentration 0.5-1.5M

Data illustrative of my invention in its several aspects are provided by the accompanying tables. Exceptiug Table II, where the swelling value in each case was .determined using newly grown hair formed in one week and was measured on the portion of the hair shaft immediately above the scalp line, the swelling values were arrived at by measurements taken about three inches removed from the scalp line using hair of three months growth. Hair which has been on the head for such a period of time has been modified by exposure to sunlight, chlorine encountered in water, mechanical action, i. e., combing and brushing, etc. and tends to swell more than does virgin new grown hair.

Table I.The swelling of hair fibers in 0.5 M ammonium thioglycolate solutions, pH 9.4, containing varying amounts of added urea Swelling,

After immersion of the wet hair in the solution for 5 minutes. All values were calculated on the dry major axis.

' Control containing urea. and no thioglyoolate.

Table II.-The swelling of hair in ammonium thioglycolate lotions containing urea and ammonium salts, taken from the portion of the shaft which is just above the scalp line Table III'.-The performance of 0.5 M ammonium thioglycolate lotions containing urea and ammonium salts with relation to swelling and-waving activity r m Composition mersion Lotion H Wave for- No. v P Rating Urea Salt (Cone) Mi fig Per- Per- M cent cent 0. 0 9. 3 -l( 47 100 1. 5 9. 3 I 81 111 1. 0 9. 3 l 86 1. 5 9. 3 54 l. 5 9. 1 61 96 2. 0 (NH4)2SO4 (0.3 M) 9. 0 60 L 5 N'H4Ol (1.5 M) 9. 3 l 61 84 Table I shows that the swelling activity of an arnmonium thioglycolate composition containing urea increases with the concentration of urea. Coincident with the .increase inswelling activity there is, as before indicated, a pronounced improvement in hair waving periormance in that less time is required to accomplish the necessary plasticization and in that tighter waves result on the neutralization of the .plasticized hair. The aforementioned over-processingof the hair ordinarily does not occur where the solution is less than 1.0 molar in the respect of the urea component vand many types of hair are not affected until a substantially higher concentration is reached.

It is interesting to note from Table II, which illustrates the elfect of the ammonium salt addition on the swelling effects of the thiol and urea, that both of the lotions combining ammonium salt swelled the hair even less than the composition which contained no urea. Yet the waving results .in each case approached those obtained with composition 2 and without the over-processing experienced with lotion 2. Clearly, this phenomenon cannot be explained in a manner consistent with my original hypoth: esiswhich, for this reason, may .Well be incorrect.

Compositions 3-7 inclusive in Table III illustrate the variations in pH, .salt concentration and urea concentration which can be made with improvement in waving results in lotions of the indicated ammonium thioglycolate concentration. It will be observed from this table that the swelling level after 30 minutes in the case of each of these ammonium salt-containing compositions was let: than the 100% obtaining in the instance of the control position, i. e., lotion No. 1. On the other hand, the rate of swelling as indicated by the minute value was greater. In each of Tables II and HI, the swelling after 30 minutes is equivalent to the equilibrium swelling.

My invention is further illustrated by the following specific examples, which are not to be taken as many way limitative of the scope thereof.

Example I A solution containing 2.6 M urea and 0.45 M am-' monium thioglycolate, brought to a pH of 9.4 by the addi tion of ammonium hydroxide, when tested on the heads of several subjects, following favorable results with hair tresses made from cuttings from human hair, was founi to allow for the impartation of a very good cold wave despite the relatively low thiol concentration.

Example 11 A composition containing 0.5 M cysteine hydrochloride and 3 M urea, adjusted to a pH of 9.4 with ammonia, plasticized the test hair to the extent required for impartation of a good wave in about 30 minutes. If the urea is omitted, very little waving activity is observed, even though the solution is left in contact with the hair for a substantially longer period.

Although I have indicated herein a preference for thiols containing neutralized acid groups, my invention may also be applied to thiol compositions in which the thiol does not comprise such a group. Thus, satisfactory resul '1 may be had with alkaline polar thiols such as fl-thioethylamine or with non-polar and essentially neutral thiols as exemplified, for instance, by fi-hydroxyethanethiol, monothiodimethyl ketone, B-monothiodiethylether, the ethyl ester of thioglycolic acid, and the various amides of thin glycolic acid.

The ammonium salts of mercaptoethanesulfonic acid and 3-mercapto-2-hydroxypropanesulfonic acid, both mentioned in the forepart hereof, while of an etfectiveness comparing favorably with ammonium thioglycolate, are not prone to cause over-processing of the hair in the presence of urea and hence do not require the employment of an ammonium salt therewith.

When using a cysteine salt or a salt of one of the above mercapto-sulfonic acids, I prefer that the compos tion of the lotion be as indicated below:

pH 9.0-9.5 Thiol concentration 0.40.8 M Urea concentration 0.5-4.0 M

claim 1 in which the thiol comprises a strong polar group.

3. An aqueous hair waving composition according to claim 2 where the polar group is a neutralized acid group.

4. An aqueous hair waving composition according to claim 1 in which the thiol is ammonium thioglycolate.

5. An aqueous hair waving composition having a pH within the range 8.6 to 9.4 and comprising ammonium thioglycolate, a urea compound capable of swelling hair selected from the class consisting of urea, methyl urea and ethyl urea, and an ammonium salt of a strong mineral acid incapable of reducing hair, said composition being from 0.4 to 0.6 molar in the respect of the ammonium thioglycolate, from 0.5 to 3.0 molar in the respect of the urea compound and from 0.5 to 1.5 molar in point of the ammonium salt.

6. An aqueous hair Waving composition according to claim 5 in which the ammonium salt is ammonium chloride.

7. An aqueous hair waving composition according to claim 5 in which the ammonium salt is ammonium sulfate.

8. An aqueous hair waving composition according to claim 5 in which the urea compound is urea;

9. An aqueous hair waving composition having a pH within the range 9.0 to 9.5 and comprising cysteine effective as a hair-reducing agent and a urea compound capable of swelling hair selected from the class consisting of urea, methyl urea and ethyl urea, said composition being from 0.4 to 0.8 molar in the respect of the cysteine derivative and from 0.5 to 4.0 molar in the respect of the urea compound.

10. An aqueous hair waving composition having a pH within the range of 9.0 to 9.5 and comprising a salt of mercaptoethanesulfonic acid effective as a hair-reducing agent and a urea compound capable of swelling hair selected from the class consisting of urea, methyl urea and ethyl urea, said composition being from 0.4 to 0.8 molar in the respect of said salt and from 0.5 to 4.0 molar in the respect of the urea compound.

11. An aqueous hair Waving composition having a pH Within the range 9.0 to 9.5 and comprising a salt of 3- mercapto-Z-hydroxypropanesulfonic acid effective as a hair-reducing agent and a urea compound capable of swelling hair selected from the class consisting of urea, methyl urea and ethyl urea, said composition being from 0.4 to 0.8 molar in the respectof said salt and from 0.5 to 4.0 molar in the respect of the urea compound.

1.2. An aqueous hair waving composition having a pH within the range 8.6 to 9.5 comprising a thiol hair reducing agent, a urea compound capable of swelling hair selected from the class consisting of urea, methyl urea and ethyl urea and an ammonium salt of a strong mineral acid incapable of reducing hair, said composition being from 0.35 to 0.8 molar in said thiol, from 0.5 to 4.0 molar in said urea compound and from 0.25 to 2.0 molar in said ammonium salt.

References Cited in the file of this patent UNITED STATES PATENTS 2,437,965 Michaels et a1 Mar. 16, 1948 2,501,184 Michaels et al Mar. 21, 1950 FOREIGN PATENTS 117,071 Australia June 3, 1943 443,359 Great Britain 1935 OTHER REFERENCES Jones et al., The Dispersion of Keratins, Archives of Biochemistry, vol. 3, Dec. 1943, No. 2, pp. 193 to 202.

Speakman et al., The Reactivity of the Sulphur Linkage in Animal Fibers, J. Soc. Dyers and Colourists, vol. 57, No. 3, Mar. 1941, pp. 73 to 81.

Mercer, Formation of Keratin, Trans J. Text. 'Inst., pp. 'T640-T649, Sept. 1949, especially at p. T647. 

1 . AN AQUEOUS HAIR WAVING COMPOSITION HAVING A PH WITHIN THE RANGE 8.6 TO 9.5 AND COMPRISING A THIOL HAIR-REDUCING AGENT AND A UREA COMPOIND CAPABLE OF SWELLING HAIR SELECTED FROM THE CLASS CONSISTING OF UREA, METHYL UREA AND ETHYL UREA, SAID COMPOSITION BEING FROM 0.35 TO 0.8 MOLAR IN THE RESPECT OF THE THIOL AND FROM 0.5 TO 4.0 MOLAR IN THE RESPECT OF THE UREA COMPOUND. 